FDA accepts application for 18F-rhPSMA-7.3 for prostate cancer

The FDA has accepted a New Drug Application (NDA) for the PSMA-PET radiohybrid imaging agent 18F-rhPSMA-7.3 for diagnostic imaging of prostate cancer, according to Blue Earth Diagnostic, the developer of the agent.1

The NDA is supported by results from one phase 1 trial and two phase 3 trials, SPOTLIGHT and LIGHTHOUSE. SPOTLIGHT data was shared at medical conferences earlier this year; however, results from LIGHTHOUSE have not yet been made available.

“Prostate cancer is one of the leading causes of cancer-related death in men worldwide, and accurate localization and staging of the disease is critical to establishing optimal medical management strategies,” Eugene Teoh, MBBS, MRCP, FRCR, DPhil, Chief Medical Officer of Blue Earth Diagnostics, stated in a press release. “We believe that the performance of 18F-rhPSMA-7.3, its high PSMA-binding affinity and potential for low bladder activity will make it a valuable diagnostic tool radiolabeled with 18F for high image quality and easy patient access.

SPOTLIGHT Data

The latest data from the SPOTLIGHT Phase 3 trial presented earlier this year at the 2022 AAU Annual Meeting showed that, compared to baseline conventional imaging, PET imaging with 18F-rhPSMA-7.3 frequently caused post-examination overstatement of disease in men with recurrent prostate cancer.2

Among 250 of 366 men in the efficacy analysis population who had negative baseline conventional imaging, 18The F-rhPSMA-7.3 showed a correct detection rate between 45% and 47%, which corresponds to the percentage of patients scanned with at least one true positive PET result compared to the standard of truth of histopathology or histopathology. conventional confirmatory imaging. Notably, staging results varied depending on prior treatment and anatomical region.

Initial data from SPOTLIGHT (NCT04186845) presented previously at the 2022 Genitourinary Cancer Symposium showed that the overall detection rate in patients who had evaluable disease 18The F-rhPSMA-7.3 analysis was 83% majority read.3

The SPOTLIGHT study recruited male patients at least 18 years of age who had previously received curative treatment for localized prostate cancer. Patients were required to have an elevated PSA that may indicate biochemical recurrence and be eligible for salvage therapy.

18F-rhPSMA-7.3 was administered at a dose of 296 MBq/8 mCi, and PET/CT scans were performed between 50 and 70 minutes after injection. The scans were then evaluated by 3 blind central readers. The standard of truth was confirmatory conventional imaging or histopathology. Biopsies were taken 60 days after the PET scans and confirmatory imaging was performed within 90 days.

Of the 420 patients who consented to the trial, 391 received 18F-rhPSMA-7.3, of which 389 underwent evaluable PET/CT. Additionally, 366 patients had enough data to determine the standard of truth; these patients constituted the population whose efficacy was evaluable. Specifically, 69 patients had a standard of truth determined by histopathology compared to imaging in 297 patients.

In this population, the mean age was 68.4 years (range, 43-85). The median PSA was 1.27 ng/mL (range, 0.03-134.6) and most patients had a Gleason grade group of 3 (30%).

Additional data showed the 18The detection rate of F-rhPSMA-7.3 was 88%, compared to a correct detection rate of 57%.

In patients with negative baseline conventional imaging in the prostate bed region, between 3.5% and 8.0% of post-prostatectomy patients showed true positive detections, compared to between 39% and 41% of post-prostatectomy patients. radiotherapy.

In patients with negative baseline conventional imaging in the pelvic lymph node region, between 18% and 21% of patients after prostatectomy showed true positive detections versus 6.5% of patients after radiation therapy. In patients with negative baseline conventional imaging in the extra-pelvic region, between 21% and 26% of patients after prostatectomy showed true positive detections versus between 20% and 30% of patients after radiotherapy.

“This event marks an important milestone in advancing our strong prostate cancer pipeline, and we are very pleased that the FDA has accepted our NDA submission for the use of 18F-rhPSMA-7.3 PET Imaging in Prostate Cancer Patients,” said David E. Gauden, DPhil, CEO of Blue Earth Diagnostics, in this press release.

“We look forward to working with the Agency throughout the review process, with the goal of having an approved product widely available and accessible across the United States. Subject to FDA approval, we think that 18F-rhPSMA-7.3 PET imaging may be clinically useful in the management of men affected by prostate cancer across the continuum of care. At Blue Earth, we all want to express our sincere gratitude to the many patients, physicians, clinical trial sites and collaborators who have worked closely with us to progress 18F-rhPSMA-7.3, and to have successfully completed our Phase 3 clinical trials despite all the challenges posed by the COVID-19 pandemic,” added Gauden.

Learn more about SPOTLIGHT:

Dr. Fleming talks about the 18F-rhPSMA-7.3 imaging agent and the SPOTLIGHT trial in prostate cancer

High Reader Reproducibility with 18F-rhPSMA-7.3 Image Interpretation in Prostate Cancer

References

1. Blue Earth Diagnostics Announces FDA Acceptance of New Drug Application for 18F-rhPSMA-7.3, a Radiohybrid PET Imaging Agent Targeted to Prostate Specific Membrane Antigen for Prostate Cancer prostate. Posted September 28, 2022. Accessed September 29, 2022. https://bwnews.pr/3y4rbRf

2. Fleming MT. Impact of 18F-rhPSMA-7.3 PET on the rehabilitation of patients with prostate cancer recurrence: results of the prospective phase 3 multicentre SPOTLIGHT study. Presented at: AAU Annual Meeting 2022; May 13-16, 2022; New Orleans, LA. Abbreviated PLLBA-02.

3.Schuster DM. Detection rate of 18F-rhPSMA-7.3 PET in patients with suspected recurrence of prostate cancer: results of a prospective multicenter phase 3 study (SPOTLIGHT). J Clin Oncol. 2022(supplement 6):9. doi:10.1200/JCO.2022.40.6_suppl.009